There are thousands of planets outside the solar system, so the chances that some of them have the necessary conditions for life are very high. But even if alien life does exist, scientists still don't know what these alien creatures might look like.
Recently, a Spanish cosmologist put forward his assumption about the size of the inhabitants of other worlds in space. He believes that most of these creatures will be very large and can weigh around 314 kilograms.
Fergus Simpson of the University of Barcelona presented his case in an article posted on the arXiv.org preprint site. His conclusions are based on a model based on Bayes' theorem.
Simpson began his calculations by determining the number of individuals that could live in a certain alien civilization and took as a basis an average number of 50 million. He argues that there are many civilizations in the Galaxy, but they are most likely not densely populated. The density of the population of most planets is average, the Spanish researcher claims, but sometimes celestial bodies with a very large or, on the contrary, very small number of inhabitants will be encountered.
To explain this, he cites the example of the distribution of people on Earth. For example, in China, the population density is about 140 people per square kilometer, while in New Zealand it is only 16.
Based on a similar argument, Simpson decided that the size of the planet supporting extraterrestrial life was likely to be smaller than the size of the Earth. In the course of simulations, he suggested that the size of 50% of the Earth begins the lower limit, because if the planet is even smaller, then it is not easy for it to preserve the atmosphere or water. For example, the parameters of Mars correspond to approximately 53% of the size of the Earth. According to Simpson, in 95% of cases, habitable planets will have a radius of 1.4 times less than the Earth.
The last part of Simpson's analysis focused on the size of the alien lifeforms. The fact is that the animals of the Earth have a certain ratio between the size of individuals and their number in the population - the smaller the creature, the more representatives of its species live on the planet. For example, there are significantly more mosquitoes than blue whales.
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The ratio between individual size and species population shows that the average weight of an alien will be about 314 kilograms - about the same as that of a bear or elk.
However, despite the fact that Simpson's assumption is based on mathematics, some researchers still believe that his statistical assumptions may be wrong. In particular, because the cosmologist relied on the laws inherent in earthly life, and on other planets everything can be completely different.
“It is unlikely that Simpson is absolutely accurate in his conclusions, in particular, in those related to the body size of aliens. The largest creatures tend to live in the aquatic environment, says Seth Shostak, a researcher at the SETI Institute for the search for extraterrestrial intelligence. - It is unlikely that a large animal will be intelligent: as you know, one of the reasons why a person has become smarter is the need to search for food. A creature of enormous size will not face many obstacles on its way to prey - so it is unlikely to develop extraordinary intelligence."